Up to August 06, China is leading America in gold medal acquisition by 36:31.  There are two days left, America has big advantage in men and women basketball, women volleyball as well; while China has only one highly possible item in men diving.  So a keen competition between the Big Two chasing for the number one place  in the ranking of gold medals will be anticipated.  

Some remaining "minor items" like boxing, wrestling, karate, yachting and so on might become the X factors to determine who is the winner.  Let us wait and see.